I'm surprised more startups don't consider selling merchandise or some simple physical product. The margins can be pretty healthy and the value proposition is pretty simple. I think the recent spate of successes on KickStarter will tip people in this direction.
If you can make something novel, ala AirBNB's Obama O's cereal it seems like an easier path to ramen than AdWords.
I think The Oatmeal started as a marketing campaign for an online dating site. Some of the older comics still have links to it.
Merchandising seems questionable, though. Consider: You have a business, and you're going to sell merchandise to promote your business. Now you have two businesses.
This is a perfectly valid strategy for a small business or a bootstrapped startup. For example, try to figure out how many different businesses 37signals is in. I'm aware of online software, books, training and advertising, and there's probably a couple of others. As they put it: "Sell your byproducts."
This strategy probably doesn't make sense for a funded startup, however.
If you can make something novel, ala AirBNB's Obama O's cereal it seems like an easier path to ramen than AdWords.